<template>
    <div
            id="header-search"
            :class="{'show': show}"
            class="header-search"
    >
        <svg-icon
                class="search-icon"
                name="search"
                @click.stop="click"
        />
        <el-select
                ref="headerSearchSelect"
                v-model="search"
                :remote-method="querySearch"
                filterable
                default-first-option
                remote
                placeholder="Search"
                class="header-search-select"
                @change="change"
        >
            <el-option
                    v-for="item in options"
                    :key="item.path"
                    :value="item"
                    :label="item.meta.title.join(' > ')"
            />
        </el-select>
    </div>
</template>

<script lang="ts">
    import path from 'path'
    import Fuse from 'fuse.js' // A lightweight fuzzy-search module
    import {Component, Vue, Watch} from 'vue-property-decorator'
    import {RouteConfig} from 'vue-router'
    import {AppModule} from '@/core/store/modules/app'
    import i18n from '@/assets/language'
    import {UserModule} from "@/core/store/modules/user"; // Internationalization

    @Component({
        name: 'HeaderSearch'
    })
    export default class HeaderSearch extends Vue {
        private search = ''
        private show = false
        private options: RouteConfig[] = []
        private searchPool: RouteConfig[] = []
        private fuse?: Fuse<RouteConfig, Fuse.FuseOptions<RouteConfig>>

        get routes() {
            return UserModule.menus
        }

        get lang() {
            return AppModule.language
        }

        @Watch('lang')
        private onLangChange() {
            this.searchPool = this.generateRoutes(this.routes)
        }

        @Watch('routes')
        private onRoutesChange() {
            this.searchPool = this.generateRoutes(this.routes)
        }

        @Watch('searchPool')
        private onSearchPoolChange(value: RouteConfig[]) {
            this.initFuse(value)
        }

        @Watch('show')
        private onShowChange(value: boolean) {
            if (value) {
                document.body.addEventListener('click', this.close)
            } else {
                document.body.removeEventListener('click', this.close)
            }
        }

        mounted() {
            this.searchPool = this.generateRoutes(this.routes)
        }

        private click() {
            this.show = !this.show
            if (this.show) {
                this.$refs.headerSearchSelect && (this.$refs.headerSearchSelect as HTMLElement).focus()
            }
        }

        private close() {
            this.$refs.headerSearchSelect && (this.$refs.headerSearchSelect as HTMLElement).blur()
            this.options = []
            this.show = false
        }

        private change(route: RouteConfig) {
            this.$router.push(route.path)
            this.search = ''
            this.options = []
            this.$nextTick(() => {
                this.show = false
            })
        }

        private initFuse(list: RouteConfig[]) {
            this.fuse = new Fuse(list, {
                shouldSort: true,
                threshold: 0.4,
                location: 0,
                distance: 100,
                maxPatternLength: 32,
                minMatchCharLength: 1,
                keys: [{
                    name: 'title',
                    weight: 0.7
                }, {
                    name: 'path',
                    weight: 0.3
                }]
            })
        }

        // Filter out the routes that can be displayed in the sidebar
        // And generate the internationalized title
        private generateRoutes(routes: RouteConfig[], basePath = '/', prefixTitle: string[] = []) {
            let res: RouteConfig[] = []

            for (const router of routes) {
                // skip hidden router
                if (router.meta && router.meta.hidden) {
                    continue
                }

                const data: RouteConfig = {
                    path: path.resolve(basePath, router.path),
                    meta: {
                        title: [...prefixTitle]
                    }
                }

                if (router.meta && router.meta.title) {
                    // generate internationalized title
                    const i18ntitle = i18n.t(`route.${router.meta.title}`).toString()
                    data.meta.title = [...data.meta.title, i18ntitle]
                    if (router.redirect !== 'noRedirect') {
                        // only push the routes with title
                        // special case: need to exclude parent router without redirect
                        res.push(data)
                    }
                }

                // recursive child routes
                if (router.children) {
                    const tempRoutes = this.generateRoutes(router.children, data.path, data.meta.title)
                    if (tempRoutes.length >= 1) {
                        res = [...res, ...tempRoutes]
                    }
                }
            }
            return res
        }

        private querySearch(query: string) {
            if (query !== '') {
                if (this.fuse) {
                    this.options = this.fuse.search(query) as any
                }
            } else {
                this.options = []
            }
        }
    }
</script>

<style lang="scss" scoped>
    .header-search {
        font-size: 0 !important;

        .search-icon {
            cursor: pointer;
            font-size: 18px;
            vertical-align: middle;
        }

        .header-search-select {
            font-size: 18px;
            transition: width 0.2s;
            width: 0;
            overflow: hidden;
            background: transparent;
            border-radius: 0;
            display: inline-block;
            vertical-align: middle;

            .el-input__inner {
                border-radius: 0;
                border: 0;
                padding-left: 0;
                padding-right: 0;
                box-shadow: none !important;
                border-bottom: 1px solid #d9d9d9;
                vertical-align: middle;
            }
        }

        &.show {
            .header-search-select {
                width: 210px;
                margin-left: 10px;
            }
        }
    }
</style>
